CN1029875C - Automative interest increasing controlling circuit - Google Patents
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- CN1029875C CN1029875C CN 92102111 CN92102111A CN1029875C CN 1029875 C CN1029875 C CN 1029875C CN 92102111 CN92102111 CN 92102111 CN 92102111 A CN92102111 A CN 92102111A CN 1029875 C CN1029875 C CN 1029875C
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Abstract
The present invention has the aim of providing a high-speed automatic gain control (AGC) circuit for the dynamic regulation of the gain of a receiver because the receiver is used by a laser scanning system for receiving reflected light from a bar code. The AGC circuit is used for detecting the final output of the receiver, besides, the AGC circuit comprises an additional feedback circuit which is connected with the output of an amplifier in the previous stage of a final amplifier for detecting the output signal of the amplifier before a final amplification stage to improve the speed of the automatic regulation of the gain, namely that the additional feedback circuit is a second feedback circuit. With the utilization of the automatic gain controlling circuit of the present invention, a scanning system can decode the bar code without being scanned for several times.
Description
The present invention relates to read the laser scanning system that bar code is used, specifically relate to automative interest increasing controlling circuit, it can dynamically adjust the gain of receiver automatically, and this receiver is the light that is used for receiving by the bar code reflection.
Up to now as United States Patent (USP) 4,496, showed that typical bar code reading system generally comprises light source, optical system and pick-up unit several sections for No. 831.Optical system comprises condenser lens, is used for that the light beam that light source sends is focused on and aim at bar code and scans; Pick-up unit is used to detect the light that is reflected by scanning target bar code.Light source is semiconductor laser diode normally.The light beam that light source produces is by penetrating on the scanning target after the optical system focusing.The scanning device of installing in the scanning head light path of device possesses at least a scan module is arranged, and it strafes on bar code laser beam.In order to make light beam pass through the outlet opening point of aim, light reflection mirror is installed on the axle of motor.Reading device detects by the light of mark reflection and handles, and it is to be made of the such photo-sensitive cell of semiconductor photo diode.Be defeated by receiver after the light that detects is transformed into electric signal, amplify, handle and decoding by receiver.
In the existing laser scanning device,, use automatic gain control (" AGC ") for the full gain to receiver is dynamically adjusted.If in laser scanning device, use AGC, even under the situation that the receiver gain of laser scanning device is fixed, also can decipher to being placed on longer-distance mark.
The AGC loop of using in the existing laser scanning device in order correctly to adjust the full gain of receiver, must repeatedly be scanned.This is because reaction time of AGC is decided by following various factors, is scanned promptly that the factors such as intensity of the ambient light of existence in the distance of form, bar code mark and scanner of target bar code mark and the scanner visual field determine.The reaction time of AGC depends on the bar code mark of ambient light condition and scanning, for example from the hundreds of millisecond, to also reaching in the scope in several seconds under opposite extreme situations.So the Chang AGC reaction time, can see in department stores, the bookkeeper is in order to decipher the bar code mark on the commodity, and the situation of use hand-held laser scanning gun comes to this.In most cases, the bookkeeper has to carry out repeated multiple times scanning in order to obtain correct decoding on same mark.
The typical A GC that is used in the bar code scanister is the gain that comes receiver control according to the peak-to-average that monitors, adjusts the output signal of receiver.Be output as from being input to of receiver and obtained big full gain, the amplifier that is cascaded of several separation has been installed.
AGC experiences in the loop terminal output of receiver, and adjusts an Amplifier Gain in the receiver preamplifier state.In fact, by forming feedback circuit by the AGC loop between the amplifier that outputs to gain adjustable of receiver.Because this feedback circuit, no matter how the amplitude of input signal changes, the output of receiver all can be adjusted into certain value.
Carry out filtering owing to AGC loop detection peak and to output signal, can obtain and the proportional direct current of the average peak of received signal (d.c.) voltage.It is compared with fixing d.c. reference voltage, and dynamically adjust the gain of receiver, to reduce the difference of reference voltage and output dc voltage.
Because AGC bring big error can for the gain of receiver to output voltage in the words of short time, big fluctuation sensitivity, for non-inductive to such fluctuation, then uses the average peak of output voltage.For example, the signal that is received according to the bar code scanner, might comprise the undesirable output bias that reflected light produced that is close to the scanned barcode wrappage, if read the average peak of output, AGC does not wish that for these signal that exists is just insensitive.Under worst situation, the average peak for the output that correctly determines receiver has the gain setting of steady state (SS) until reaching AGC, just is necessary to read the input signal in several cycles.In some cases, AGC has to take a long time in order to obtain the gain setting of final suitable receiver.
For given input, AGC will reach the needed time of steady state (SS) and be called " starting time ".But, when receiver has only single feedback circuit, shorten the starting time in AGC loop, the amplitude error of steady state (SS) output signal will increase.According to tradition, the deviser bears the design of AGC, improves precision and shorten the starting time conflicting.Such design result, in order to satisfy the desired precision of system, AGC just becomes low speed.
The AGC sensitive time also is subjected to output signal memory in the restriction that big low-frequency component is arranged except that being subjected to the starting time restriction.Worry that big low-frequency component can make output amplifier saturated.Output amplifier one is saturated, because receiver is set gain, and the radio-frequency component of the output signal of use just be limited (cutting).Thereby the action of the gain setting of AGC just can't realize.Under opposite extreme situations, the saturated gain setting of receiver of giving of output amplifier brings very big error, thereby, worry to scan the decoding failure of mark.
In view of the feature and the restriction in typical A GC loop as mentioned above, the response time that makes receiver reach steady state (SS) aggravates, and strong hope can have a kind of AGC loop that can adjust the full gain of receiver rapidly.Thereby purpose of the present invention just is to provide a kind of automatic gain loop, feasible restituted signal in a short period of time.
The present invention has the automative interest increasing controlling circuit that can dynamically adjust in the full gain of the receiver of bar code scanning system in mind.This automative interest increasing controlling circuit can make receiver that possible decoded signal is provided in a short period of time, and thereupon, the response time of receiver can improve, thereby the full gain of receiver is adjusted rapidly.In order to be adjusted rapidly, this automatic gain control circuit includes other feedback circuit, and it is connected on the amplifier of terminal amplifier former configuration of receiver.The received signal of the target bar code that the output of this amplifier and the end of receiver output expression are same, but the terminal output of amplitude ratio is little.
The starting time of the additional feedback circuit of receiver is almost negligible, the steady state (SS) that can the infer receiver at a high speed due form that gains, thereby the regulating the speed of gain of improving receiver.In addition, additional feedback circuit is also responded to the electronic unit initial stageization that makes AGC and the d.c. signal that uses.AGC one is near steady state (SS), and additional feedback circuit just begins to disconnect from AGC, thus, just can correctly be finely tuned the gain of receiver by the primary feedback circuit of receiver output.
Below will describe in detail, because the AGC sensitive time has been improved in AGC of the present invention loop, for with by the distance of scanner to bar code, light intensity around in the scanner visual field, existing, and the response time of the relevant receiver of the factors such as character of sweep signal bar code mark also obtain bigger improvement.Except that the improvement of AGC response time, the full gain of receiver is more effectively dynamically adjusted in AGC of the present invention loop on the basis of not sacrificing precision.
Brief description of drawings:
Fig. 1 is the block scheme of existing automative interest increasing controlling circuit.
Fig. 2 is the block scheme of automative interest increasing controlling circuit of the present invention.
Fig. 3 is the block scheme of the 2nd embodiment of automative interest increasing controlling circuit of the present invention.
Fig. 4 is the wiring diagram of automative interest increasing controlling circuit of the present invention.
Fig. 5 is the laser scanning gun sketch.
Fig. 1 is the block diagram of the general automative interest increasing controlling circuit 10 that uses for the gain of control laser scanning system receiver.This block representation goes out between input signal (VIN) and output signal (VOUT) to have only single feedback circuit.Receiver has the third stage amplifier 16,18 and 20 of separation at least.The action of AGC is not subjected to the restriction of the progression of the amplifier that uses in the receiver.The progression of used amplifier depends on the limit gain of amplifiers at different levels of use and the maximum gain that requires fixed receiver according to purposes.The voltage gain K1 of amplifier 18, and the voltage gain K2 of amplifier 20 fixes respectively, has only the voltage gain K(Vg of amplifier 16) be variable, it is subjected to error voltage signal 22(Vg) control.
According to average peak voltage signal that exists on the AGC capacitor 34 and fixing reference voltage 36(Vr), for example can be fixed as 1.2 volts of DC voltage, compare by amplifier 30, the automatic gain control action just dynamically takes place.In essence, the gain of amplifier 16 is determining the full gain of receiver, and this adjustment is to make the voltage difference of voltage signal 36 and 32 become minimum value by amplifier 30 to obtain.The deviation voltage signal 22 of representing this voltage difference is by amplifier 30 outputs, the impedance that comes the feedback circuit 38 of control amplifier 16 with deviation voltage signal 22.In order to adjust yield value, with the input end of deviation voltage signal 22 input transistors 40, utilize the characteristic of field effect transistor 40, dynamically control the impedance between its drain electrode 42 and the source electrode 44.This impedance that can control is connected in parallel on the resistance 46 in the feedback circuit 38, thereby, can change the gain k(Vg of amplifier 16).Automatically adjust the gain of amplifier 16 with deviation voltage signal 22, all be fine as for what method of employing.For example in the present embodiment, use be JFET(junction field effect transistor as the action of Control of Voltage resistance).Use the transistor or the integrated circuit of other model also can obtain same gain adjustment.Making the voltage difference of the input existence of amplifier 30 is minimum value, adjusts output signal 14 with this and is certain amplitude.Because such version makes output signal 14 not be subjected to the influence of input signal 12 changes.
Though existing technology AGC loop 10 is point-device, make output signal 14 reach many cycles that this steady state value just needs input signal 12.As previously mentioned, this just becomes the slow reason of AGC capacitor 34 charging rates in the feedback circuit.Thereby AGC is suitable gain to adjusting receiver, will spend the long time.
Fig. 2 is the block scheme of automative interest increasing controlling circuit 100 of the present invention.As shown in the figure, its first circulation 110 in essence with shown in Figure 1 be identical AGC loop and receiver, for discerning cross reference number same on the same composition scale.Noticeable characteristics are the 2nd circulation 70 in the loop 100, and this circulation is used for the output signal of detecting amplifier 18.This additional response time of improving AGC that is fed back to provides two kinds of functions.First function is that this circulates with reference voltage 50(by adding circuit 53) come inducing DC voltage, use this DC voltage to make the 34 initial stage charging of AGC capacitor.This voltage adds a bias voltage for amplifier 30 in its range of linearity, transistor 40 is offset near this threshold voltage.Capacitor 34 initial stageizations back changes the gain that just can change receiver on this voltage basis, got rid of " the not sensitive time " of AGC in fact.
Second function that this circulation provides is electric capacity 34 chargings of giving AGC with the output (by adding circuit 53) of amplifier 18.Filtering is not carried out in the output of amplifier 18, and capacitor 34 can be ignored the starting time and charge.This circulation can make receiver with the last gain-state of high speed estimating.
The amplitude specific output 14 of output 52 that these circulation 70 attendant advantages of bringing are amplifiers 18 is little, even signal 52 is not limited yet when the last output of receiver 14 reaches capacity, thereby can better express received signal 12.Receive under the terminal output in back 14 situations about reaching capacity at big low frequency ambient signals, use signal 52 that the gain of receiver is descended, thereby amplifier 20 is restored by saturated.
On AGC capacitor 34, add the 2nd feedback cycle 70 again, under the condition of the precision that does not reduce the steady state (SS) gain setting, improved the overall response time in AGC loop 100 with first feedback cycle 110.Because before the gain of receiver reached steady state (SS), the 2nd circulation 70 was from 34 automatic cutouts of AGC capacitor, precision is unaffected.Voltage one on the AGC capacitor 34 increases, and the gain of receiver descends, and makes the signal amplitude of output 52 of amplifier 18 reduce, and the 2nd circulation does not make gain setting be affected.Because AGC one reaches steady state (SS), the voltage on the AGC capacitor 34 is just by diode 54(D) cause that disconnects, the 2nd feedback cycle 70 just disconnects from AGC.The cut off of diode 54 is corresponding to this point of the gain of receiver when it only exceeds the gain K of amplifier 20 than steady state (SS).In fact, circulate 70 at a high speed, can in the error range of K, infer the due state of gain of receiver.In case the 2nd circulation 70 after AGC electric capacity 34 disconnects, is just finely tuned by the gain of 110 pairs of receivers of the 1st circulation.
Fig. 3 is another embodiment of automative interest increasing controlling circuit 100.In this embodiment, consist of the Hi-pass filters of the 2nd circulation in 120, have only the alternating component of the 2nd grade of output signal 52 to be defeated by on the capacitor 34 of AGC by capacitor 56 and resistance 58.As a kind of selection, it is also passable to carry out the initial stage charging with resistance 99 by 50 pairs of AGC capacitors of reference voltage 34.The size of initial stage voltage is decided by the bleeder circuit of forming of resistance 99 and 58.The composing principle of capacitor 56 and resistance 58 is to make its cutoff frequency that obtains much lower more than the cutoff frequency of the Hi-pass filter 24 that uses in the 1st circulation 110, selects the value of capacitor 56 and resistance 58 by this principle.By the high pass filter filters of the 2nd circulation in 120, only be added in voltage on the AGC capacitor 34 as its initial stage charging with the alternating component of the 2nd grade of output signal 52.
The detailed circuit diagram of the automative interest increasing controlling circuit 100 of the AGC loop correspondence that Fig. 2 represents in detail as shown in Figure 4.The input voltage signal of Fig. 4 is that the voltage signal that partly obtained by the photoelectric sensor that back-biased photodiode 60 is a receiver is after amplifying and obtain.Photodiode 60 moves as the photocontrol current source.The output current of photodiode 60 is added on the amplifier 62 of receiver, and shows negative voltage at the output terminal of amplifier.Receiver sheet is shown by the different operational amplifier of 5 gain per stages forms the amplifier series circuit.Because high frequency and the low frequency characteristic slope of a curves that have much at one at different levels, the 3db point of high pass and low pass is arranged about 27KHz and 230Hz separately, obtain sharp bandpass filter.High-pass filtering is used and is exchanged the capacitor 71 that connects usefulness, connects with the interchange that reaches amplifiers at different levels.Exchange to connect with the flip-flop of capacitor 71 prevention input signals 12 by, also stop by the low-frequency fluctuation that brings in the scan vision.Low-pass filtering uses the capacitor 72 and the feedback resistance of amplifiers at different levels to compose in parallel.The full gain of pair amplifier is dynamically adjusted, and corresponding to amplifier shown in Figure 2 20, is about 4V for the output peak value waveform of amplifier 66 maintains here.As previously mentioned, this dynamic adjustment is by using JFET transistor 40 to reach as the Control of Voltage variable resistor in the feedback circuit of amplifier 64.The source electrode 44 of transistor 40 and 42 the resistance of draining, thus the gain of decision amplifier 64 is subjected to being added in the control of the error voltage signal 22 on the grid 43.This error amount is decided by the voltage that amplifier 30 amplifies, promptly amplifier 30 amplified output signal 14 through the difference of rectification, filtered alternating component and fixing reference voltage 36 and voltage.
The constituent of Hi-pass filter 24 shown in Figure 2 is represented with capacitor 74 and resistance 76 in Fig. 4.Using resistance 89 is in order to limit the output impedance of Hi-pass filter.At the AGC capacitor 34 of the peak detctor 28 shown in Fig. 1,2 and 3 and the average peak 32 of resistance 78 and 80 common memory amplifier 66 steady state (SS) output voltages 14.What hope aroused attention is to be formed the discharge circuit of AGC capacitor 34 by resistance 78 and 80, thereby is determining the die-away time of automatic gain control.Usually these resistance values are all very big, generally all are unit with the megaohm.
The 2nd circulation (the AGC loop 100 among Fig. 2) in AGC loop comprises divider resistance 82 and 84 and diode 54.As previously mentioned, the use of this circuit is in order promptly DC voltage to be remembered on AGC capacitor 34.This DC voltage is to be that the dc offset voltage that exists in the output of amplifier 65 extracts in Fig. 4 by amplifier 18.And being input reference voltage 50 by amplifier 65, this bias direct current voltage obtains.Initial stage voltage in memory on the capacitor 34 makes near the output offset point threshold voltage of transistor 40 of amplifier 30, therefore, has got rid of " the not sensitive time " of AGC in fact.Because the alternating component of amplifier 65 outputs is also charged to AGC capacitor 34, thereby has improved the response time of AGC.The output of amplifier 65 and receiver output signal 14 are anti-phase (differing 180 °), and this has also improved the response time.This is because this phase differential makes by the represented input signal 12 of the output of amplifier 65 and 66, the cause of jointly AGC capacitor 34 being charged with positive vibration and negative vibration.
The passive component of the embodiment of the invention shown in Figure 4, the sum of amplifier in the value of active parts and the receiver, please note the LS2000 laser scanning system of " Symbol Technologies " company manufacturing of New York, United States, it can satisfy particular system institute requirement suitably.Principle of the present invention and professor can both adopt and be fit to for any receiver apparatus that uses in the laser scanning system.
The present invention also can be achieved in portable laser scanning bar code reading device shown in Figure 5.As a desirable embodiment, reading device 200 is gun type devices, it has handle 153 and movable platen machine 154, allow gun barrel aim at the mark that will read, pull the plate machine, light beam 151 and detection loop just begin to devote oneself to work, therefore, if device is the built-in battery type, can prolong the serviceable life of battery.In the light plastic shell 155, the LASER Light Source of packing into, detecting device 158, light path and signal processing circuit, central processing unit CPU140 and power supply are battery 162 etc.The front end of shell 155 is provided with the window 156 of light transmission, and output beam 151 1 shoots out, and folded light beam 152 just might enter window.This reading device 200 is designed to leave certain distance (being contactless for mark promptly) with mark.Or mark there is not a device of the aiming bar code of transverse movement.Typical example, the portable bar code reading device of this model is being operated in several inches scopes greatly, specifies the scanning of mark being made per second 36 times.
Shown in Figure 5, scanning light beam focuses on the bar code mark on the suitable reference surface, uses suitable lens 157 to focus on (or a plurality of lens combination).For light beam is mapped on the optical axis of lens 157, adjust and determine the position of semiconductor laser diode light source 146.Light beam is by demifacet light-permeable lens 147 and other lens or by light beam formation device, connection sweep motor 160 is equipped with scanning mirror 159 when pulling plate machine 154 on the scan module, and light beam is mapped on the scanning mirror 159.If the only invisible light that light source 146 is produced then can aim at optical system,, the aiming photofixation can be got off if be necessary.Perhaps produce the visible light scanning same with laser beam.Use visible light, the user can come the point of aim with reading device before pulling the plate machine.
Below just the present invention relates to linear bar code or single line bar code aspect is described, but the present invention is not limited only to the embodiment of this class, can also be applicable to the scan pattern of more complicated, perhaps " mark 49 " and similar overlapping type bar code mark, or other two-dimentional bar code marks also can be suitable for.It is also conceivable that using method of the present invention discerns other markings as literal, perhaps the information of the feature of sensitive scanning body surface makes various visual machines with this, perhaps optical character identification device.
More than the finishing of various embodiment because the element of scanner can be assembled in the plug-in unit of superprecision, therefore, scanner can manufacture single printed circuit board or dress up incorporate micromodule.Such micromodule can exchange use as laser scanning component in the data acquisition system (DAS) of various different models.For example, micromodule can use in above-mentioned handheld scanner, be contained in the flexible handle, perhaps table surface is extended, be installed in meticulously wherein, or be installed in the downside on worktable top, perhaps will compare the annex of exquisite data acquisition system (DAS) or attached assembly and be installed in that use all is fine in the scanner of worktable top.
Micromodule preferably includes with the lower part, promptly comprises scanning element, photodetectors etc. such as rack-mount laser/light assembly, rotating mirror or to-and-fro movement mirror.For can be the circuit communication of the miscellaneous part of microcard and data acquisition system (DAS), can plug be installed in the end or the outside of microcard, control line or data line are connected on the plug, so that be connected with the socket of the miscellaneous part of system.
Each microcard each has specific scan characteristic or decoding characteristic, also can be used for a certain operation distance, perhaps specific mark or printing density is discerned.These characteristics, can manually set with the attached gauge tap of plug-in unit, the user can adopt different data acquisition system (DAS)s for dissimilar article are scanned, and also can make system be applicable to different ranges of application by the microcard that uses plug swap data acquisition system.
By above explanation, the scanning microcard will realize it being possible in data acquisition system (DAS), be called the built-in data acquisition system (DAS).Microcard comprises the parts such as keyboard, display, data storage, application software and database more than 1 or 1.Such system comprises adding modulation-demodulation device or isdn interface, perhaps movable end device sends with low-power radio between the static receiver, the communication interface that can allow other parts of the interior communication network of data acquisition system (DAS) and (institute) carry out communication.
The feature more than 2 or 2 of comprehensive the above various feature, it all is useful being applied to the scanner of other types or being applied to read with above-mentioned different bar code device, this is conspicuous, more than the invention has been described with regard to gratifying embodiment, those skilled in the art can not depart from the scope of the present invention and can change its shape and part, and this also is clearly.
Claims (15)
1, include the working gain device and can make the target reflection bright dipping produce signal optical devices receiver and the automative interest increasing controlling circuit that can dynamically adjust working gain is arranged, composition is in the scanister that can scan repeatedly above-mentioned target, this automative interest increasing controlling circuit comprises can detection signal and above-mentioned working gain carried out the first feedback line device in the self-adjusting receiver, it is characterized in that, also comprise
Can detect above-mentioned same signal and improve the second feedback line device in the receiver of regulating the speed of above-mentioned working gain.
2, the automative interest increasing controlling circuit of putting down in writing according to claim 1 is characterized in that the 2nd feedback line device has the device that reduces working gain before making above-mentioned working gain till reaching steady state value.
3, the automative interest increasing controlling circuit of putting down in writing according to claim 1 is characterized in that the 1st feedback line comprises with lower device: the receiver output signal of light intensity of expression target reflection carry out providing after the filtering alternating component filter and
With ask for after the above-mentioned alternating component rectification average peak voltage signal fairing and
The peak detector that is attached on the fairing and the value of above-mentioned average peak voltage signal is kept get off.
4, the automative interest increasing controlling circuit of putting down in writing according to claim 3 is characterized in that the 2nd feedback circuit includes the device that can shorten the acquisition average peak required time of voltage signal.
5, the automative interest increasing controlling circuit of putting down in writing according to claim 4, it is characterized in that including to the expressed deviation voltage signal of the average peak voltage signal and the voltage difference of fixing reference voltage carry out drift correction device and
Make above-mentioned deviation voltage signal become minimum and dynamically adjust the adjusting gear of receiver gain.
6, the automative interest increasing controlling circuit of putting down in writing according to claim 5, it is characterized in that it includes allows the seal of the 2nd feedback circuit and the 1st feedback circuit mutually insulated, because the input end of the drift correction device of the 2nd feedback circuit and the 1st feedback circuit are common, therefore need be with the 2nd feedback circuit and the 1st feedback circuit mutually insulated when the gain of receiver reaches steady state (SS).
7, the automative interest increasing controlling circuit of putting down in writing according to claim 6, it is characterized in that the 2nd feedback circuit comprises the device that the input of drift correction circuit is carried out the initial stage correction, its principle is to utilize and the irrelevant fixedly DC voltage of the signal that obtains from target reflection light.
8, the automative interest increasing controlling circuit of putting down in writing according to claim 6, it is characterized in that receiver comprises the 1st, the 2nd at least, and the amplifier of the 3 three grade of series connection, first feedback circuit detects the output of above-mentioned 3rd level amplifier, the 2nd feedback circuit detects the output of above-mentioned the 2nd grade of amplifier, and the 2nd grade of amplifier is connected between the 1st grade of amplifier and the 3rd level amplifier.
9, the automative interest increasing controlling circuit of being put down in writing according to Claim 8 is characterized in that its 1st grade of amplifier has variable gain control.
10, the automative interest increasing controlling circuit of putting down in writing according to claim 9 is characterized in that the 1st filter is a Hi-pass filter.
11, the automative interest increasing controlling circuit of putting down in writing according to claim 10 is characterized in that the 1st grade of amplifier is operational amplifier, and it includes the adjusting gear that is changed resistance by Control of Voltage.
12, the automative interest increasing controlling circuit of putting down in writing according to claim 11 is characterized in that the device of Control of Voltage change resistance is a field effect transistor.
13, the automative interest increasing controlling circuit of putting down in writing according to claim 6 is characterized in that seal is a semiconductor diode.
14, the automative interest increasing controlling circuit of putting down in writing according to claim 13 is characterized in that the output of 3rd level amplifier and the output of the 2nd grade of amplifier provide phase place opposite output signal.
15, the automative interest increasing controlling circuit of putting down in writing according to claim 14 is characterized in that the 1st, the 2nd, reaches the 3rd level amplifier capacitor series coupled of series connection mutually.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 92102111 CN1029875C (en) | 1992-04-01 | 1992-04-01 | Automative interest increasing controlling circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 92102111 CN1029875C (en) | 1992-04-01 | 1992-04-01 | Automative interest increasing controlling circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1077038A CN1077038A (en) | 1993-10-06 |
| CN1029875C true CN1029875C (en) | 1995-09-27 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 92102111 Expired - Lifetime CN1029875C (en) | 1992-04-01 | 1992-04-01 | Automative interest increasing controlling circuit |
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| CN (1) | CN1029875C (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| WO2009008458A1 (en) * | 2007-07-09 | 2009-01-15 | Advantest Corporation | Correction circuit and test device |
| CN107144239A (en) * | 2016-03-01 | 2017-09-08 | 杭州腾聚科技有限公司 | A kind of Gain Automatic adjusting method of handheld structure light spatial digitizer |
| CN109450461A (en) * | 2018-12-30 | 2019-03-08 | 芜湖真玛信息科技有限公司 | A kind of frequency-modulation earphone |
| KR102684575B1 (en) * | 2019-02-26 | 2024-07-15 | 에스케이하이닉스 주식회사 | Signal receiver circuit, semiconductor apparatus and semiconductor system including the same |
| CN111934779B (en) * | 2020-07-06 | 2021-07-16 | 杭州电子科技大学 | Laser signal recovery module, multi-point alignment underwater laser communication system and method |
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| CN1077038A (en) | 1993-10-06 |
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